1. Field
This application relates in general to UMTS (Universal Mobile Telecommunications System) and in particular to a method and apparatus for monitoring paging and broadcast system information in universal mobile telecommunications system user equipment.
2. Background
In a typical cellular radio system, mobile user equipment (UE) communicates via a radio access radio network (RAN) to one or more core networks. User equipment (UE) comprises various types of equipment such as mobile telephones (also known as cellular or cell phones), lap tops with wireless communication capability, personal digital assistants (PDAs) etc. These may be portable, hand held, pocket sized, installed in a vehicle etc and communicate voice and/or data signals with the radio access network.
The radio access network covers a geographical area divided into a plurality of cell areas. Each cell area is served by at least one base station, which may be referred to as a Node B. Each cell is identified by a unique identifier which is broadcast in the cell. The base stations communicate at radio frequencies over an air interface with the UEs within range of the base station. Several base stations may be connected to a radio network controller (RNC) which controls various activities of the base stations. The radio network controllers are typically connected to a core network.
UMTS is a third generation public land mobile telecommunication system. Various standardization bodies are known to publish and set standards for UMTS, each in their respective areas of competence. For instance, the 3GPP (Third Generation Partnership Project) has been known to publish and set standards for GSM (Global System for Mobile Communications) based UMTS, and the 3GPP2 (Third Generation Partnership Project 2) has been known to publish and set standards for CDMA (Code Division Multiple Access) based UMTS. Within the scope of a particular standardization body, specific partners publish and set standards in their respective areas.
Consider a wireless mobile device, generally referred to as user equipment (UE) that complies with the 3GPP specifications for the UMTS protocol. The 3GPP 25.331 specification, version 7.5.0 Release 7, referred to herein as the 25.331 specification, addresses the subject of UMTS RRC (Radio Resource Control) protocol requirements between the UMTS Terrestrial Radio Access Network (UTRAN) and the UE. Clause 8.5.7 of the 25.331 specification describes a protocol for open loop power control wherein system information from the network is used to calculate an appropriate transmit power level of a connection request message by the UE. One of the factors received is uplink interference contained in System Information Block 7 (SIB7) broadcast by the network. The UE wakes up at regular intervals to monitor the paging indicator channel in order to be able to respond to an in-bound call. In order to preserve battery service life, the UE sleeps between these waking periods.